In the paint department of body shops, there are techniques that have been developed to find a paint mix for a panel to be painted that matches the color of non-damaged panels of the vehicle. There are standard metal test panels (4″ by 6″ used in North America) that are painted with the proposed paint mix. Such a test panel 50 with a hole 52 is shown in FIG. 1. The paint mix is painted on test panel 50 and then compared to the vehicle panels that are not to be painted to determine whether the match is suitable.
Typically, the test panels are attached with tape to a wooden stick like a paint stirring stick. The painter holds the wooden stick and sprays the paint on the test panel. Often, the painter also gets some paint on their hand in the process due to overspray. To determine whether the proposed paint mix is appropriate, one person holds the test panel next to the car and another person stands back to evaluate. The person holding the panel can rotate the test panel, as needed, to get the view of the paint at various angles. Depending on the type of paint, e.g., metallic, mica, or fully-pigmented colors, the paint changes color depending on the viewing angle. For paints that exhibit this phenomenon, particularly metallic paints, it is important to view the match of the paint face on, at a slight angle, and a steeper angle. A single person can assess the match on their own, i.e., without someone holding the test panel, by taping the test panel to the car and standing back to view it. That person readjusts the test panel onto the car using tape multiple times to obtain the desired viewing angle, possibly leaving adhesive on the vehicle's panel. In yet another alternative, the painter attempts to assess the match holding the wooden stick at arm's length and adjusting the angle. Arms length is marginal, at best. Usually such a technique is insufficient to obtain a proper assessment. After a suitable match is determined, the test panel with the proper paint mix is removed from the stick. The stick is disposed of and the test panel is retained in a catalog, often secured through hole 52 of test panel 50.
The process can be cumbersome requiring multiple people or requiring a number of trips back and forth between the car and a viewing position to obtain the desired angle of the test panel on the vehicle. Furthermore, the process can be unrepeatable because it is difficult to obtain the same, suitable angle using tape and also unrepeatable with a human hand holding the test panel next to the vehicle.